Rocking and reclining chairs commonly include some form of spring mechanism between their base portions and lower structure of the chair itself to enable the chair to rock freely in forward and rearward movements. Rocking and reclining chairs have been known to generate disturbing noise as the springs are extended and compressed. Rocking-type chairs commonly provide a two-spring rocker spring assembly between the stationary base and lower structure of the chair frame for biasing the chair in an upright, neutral position while enabling the chair to rock forwardly and rearwardly. As a seat occupant rocks, the chair follows the contour of a rocker block disposed on the chair frame and supported by the stationary base. As the chair is rocked forwardly and rearwardly, the individual springs of the two spring set of the rocker spring assembly positioned on each side of the chair are alternately extended and compressed. This extension and compression of multiple springs can cause them to generate undesirable spring noise.
A second source of noise may occur when the rocking chair is rocked too far forward or rearward such that the moveable chair frame contacts the stationary base, a nearby wall, or the floor causing a knocking or bumping sound. Such motion of the chair frame relative to the base can also create an unbalanced condition for the chair or create a situation where objects may be trapped or compressed between the chair frame and the base or the floor as the chair is rocked. To help alleviate this condition, U.S. Pat. No. 5,567,009 to Fay et al., commonly assigned to the assignee of the present invention and incorporated herein by reference, discloses limit rods positioned at outside ends of a double-spring rocker spring assembly which function to limit the displacement of both springs.
The Fay et al. design is successful in limiting displacement of the two spring rocker spring assembly and therefore in reducing the knocking or bumping sounds of the second source described above. The Fay et al. design also successfully provides for sound suppression of the two-spring rocker spring assembly relative to the first source, but further improvement in sound suppression of the noise generated by alternate compression and expansion of the pairs of springs is warranted, as well as reduction in the assembly costs.